A 42-year-old woman from rural Rajasthan presents with a 4-month history of progressive lower back pain and bilateral lower limb weakness. Examination reveals paraplegia (Grade 2/5 bilaterally), sensory loss below L4, and a palpable kyphotic deformity at the lumbosacral junction. She has a history of pulmonary TB treated 2 years ago. Plain radiographs show collapse of L4 and L5 vertebral bodies with loss of disc space height. MRI shows cord compression at L4–L5 from a combination of vertebral collapse, granulation tissue, and a posterior epidural mass. Which of the following is the most appropriate next step in management?